Solar power Basics

[D.I.M.1]

I'm working on a project see (Wind power help please!)
But that aside can anyone answer my questions:

What I the weight of the average solar panel?

How much do they cost?

Ratio of power generated to sunlight?

Process in which they convert light to energy?

Also, best angle for receiving power?

Thakyou and hope you can get back to me.

[GreenPowerManiac]

Weight per panel varies with size. Mine are custom built and weigh about 25 pounds for 72 watts. Commercial weights may be between 25-100 pounds each, like I said, by size.

Cost: Since I built them myself, an average of $140 each
Bought commercially it varies greatly. I've seen them as cheap as $180 per panel for 75 watts and expensive as $800.00 for the same thing except different make/model.

The size of the cells will give you certain volts/amps output. Bigger the cell, more power output. Mine are 4x4" cells: .5 volts each and minimal amps in full sunlight.

There are a few different types of cells. Poly crystalline Silicon are abundant. http://www1.eere.energy.gov/solar/tf...ystalline.html

How a solar cell works: http://inventors.about.com/library/i...s/blsolar3.htm

Best angle depends on your climate and available exposure to the south. Most collectors are around 30-60 degrees angle. Some fancier systems follow the suns movement.

[D.I.M.1]

I'm Looking more so for solar panels that are practical for use on moving objects, and how much would be required to be efficient? Any suggestions? Also, what are the dimensions for them? LxWxH?
Also, any other information that would be relevant for powering a moving object.

GreenpowerManaic thank you very much for your reply.
-D.I.M.

[BB.]

A solar panel costs, very roughly, $3-$5 per watt rating in larger sizes and with volume purchases.

You can look at our host's website for pricing and suggested vendors.

Here is a standard 175 watt solar panel spec. sheet. Others are going to be similar. Weighs around 33 lbs.

In another thread, you asked about marine use--salt spray is a killer for aluminum frames and electrical connections... You would need to find a "marine" rated version for your needs (there are some--not sure if they are any better than standard shore versions).

Remember too that this panels are 1/8" thick tempered glass panels. If this is on a sailing ship (guessing)--they need to be away from where lines and tackle can drop--and solar electric panels need to be shade free... Any shading will dramatically reduce power output (by 50% to near 100% if full shade).

If this is an ocean going application (vs inland/bay use)--I would doubt that they would survive their first gale. Imagine mounting 2'x3' single pane windows on such a vessel. Wave and wind rip off metal deck hatches--let alone 1/8" window glass.

-Bill

[Cariboocoot]

A little "abstract reasoning" here:

Based on the 175 Watt panel. 1 electrical HP = 746 Watts = 4.25 panels @ 33 lbs. each = 140.25 lbs. per HP
And that's at 100% efficiency and just the panels' weight. An economy car has a power-to-weight ratio of around 20 lbs. per HP. Each panel is approximately 6 sq. ft. * 4.25 = 25.5 sq. ft. "Footprint" of a small car = 5' * 15' = 75 sq ft. The panels for 1 HP would take up 1/3 the area of the car.

Want to see how bad it gets? Add the over-all efficiency of a solar conversion on a flat plane of about 50% - that is, the power is cut in half. Add the weight of the mounting, wiring, and other electrical necessities as well as the weight of the vehicle itself.

This is why you don't see solar powered cars around.

[D.I.M.1]

Cariboocoot does the weight of the panel require more power to move itself than the amount the panel produces? Also, consider the ocean, unlike roads which don't move by just gaining a certain amount of momentum, one could move at a constant rate of speed. I'm still looking into it.

[Cariboocoot]

Cariboocoot does the weight of the panel require more power to move itself than the amount the panel produces? Also, consider the ocean, unlike roads which don't move by just gaining a certain amount of momentum, one could move at a constant rate of speed. I'm still looking into it.

How fast do you want to move it? Weight * Speed / 375 = HP needed (approximately). In theory you can move 20 tons with 0.1 HP (or any ratio) if you don't want to go fast. Consider a tractor: 8,000 lbs. plus load moved with 50 HP. But it doesn't go 60 MPH and it won't accelerate very fast either.

As for moving through water vs. air, water is more difficult because it is denser. Part of a ship (even a hydroplane) is always in the water. Otherwise moving mass is moving mass: a certain amount of power is required to overcome the inertia, and then once momentum comes into play considerably less power is required to keep it moving. More power must then be applied to get it to stop (inertia again: Good ol' Isaac Newton!)

At any rate, you still have the basic problem of loss of power from conversion.

You know why we keep using fossil fuels? Because they're a very compact source of a large amount of energy. Even after losses, there's plenty left over to do the job.

[dwh]

Cariboocoot does the weight of the panel require more power to move itself than the amount the panel produces? Also, consider the ocean, unlike roads which don't move by just gaining a certain amount of momentum, one could move at a constant rate of speed. I'm still looking into it.

It works that way in space, but not in the friction and surface tension of water.

It's a takes a LOT more energy to plow though water than it does to roll down a road. An 80,000 lb. boat needs a couple of 500hp engines to move at even 1/4 the speed easily attained by any semi-truck of the same weight.

I think you said you were looking to power a commercial fishing vessel from renewable energy...

Well, here's a *little* one:

http://www.maritimesales.com/HAR10.htm

With a single 500hp engine it can do 9 knots. But forget about the motive engine for a minute and look at the generator specs..."3304 Caterpillar 106 KVA and 85 KW".

Holey moley! Why so much generating capacity? Because you gotta keep the fish fresh and that requires a LOT of cooling. So not only do you have to move the hull itself around, but also have to power the *systems* installed on the boat.

GOOD LUCK powering that with solar or wind. Oh...theoretically you could replace the fuel tankage with batteries and recharge them with solar and wind...but it wouldn't be commercially feasible because it would take soooo long to recharge with the small solar and wind systems that you might be able to fit on a little 75' fishing boat.

And LOOK at that rig...I can see mounting a wind turbine on the bow, but there's little or no room to mount solar panels. At least with a semi-truck you could cover the tops of the trailers with solar panels - can't do that on a working fishing boat.


With the small RE system you could fit to a commercial fishing vessel - you might be able to run a water-maker and a hydrogen generator:

http://www.switch2hydrogen.com/

Then you could use the hydrogen to power an electric generator:

http://www.axane.net/gb/products/com...mpac_base.html

And you might be able to work it out so that the whole RE system produces maybe 1/4 of what you need to keep the fish cold...

[D.I.M.1]

dwh thank you, but for solar power, I'm thinking of creating a solar shell, or canvas.
It will form a sort of shell around it to collect energy using at least 60% of the entire surface area of the vessel, of say around 30'-50' along with that I'm still bouncing the shape of the hull from either the traditional V-hull or a catamaran. Also, to incorporate hydro power the amount of drag provided by a turbine being used to rune the water being pushed against the vessel would be inefficient, instead using the turbine's weight to perform a function it will serve as the anchor, and if it is possible collect power by using under sea currents on the bottom of the ocean. The will be a funnel with a grate to prevent clogging, and ensure maximum flow intake. Of course this idea is all just conceptual, and I have absolutely no idea if it is even feasible, but the turbine anchor will be modeled after a fortress anchor, with a few modifications, the turbine will be attached to the top part and be covered to protect it.
See link for image:
http://images.doba.com/products/1508/26266.gif

[dwh]

Marine hydro generation isn't new at all - but they normally use wind to drive a sailboat and siphon off some of that energy to generate electricity.

These systems *can* be used on a power boat to use water flowing past the hull to generate electricity...but why would you? It would be more efficient to just bolt an alternator onto the engine.

http://books.google.com/books?id=j3B...erator&f=false